Consumers expect cosmetic skin- and hair-care emulsions to satisfy a range of requirements. Apart from the cleaning and skin-/hair-care effects, value is placed on such diverse parameters as very high dermatological compatibility, good lipid-layer-enhancing properties, elegant appearance, optimal sensory impression and stability in storage.
Besides a number of surfactants, preparations used to clean and care for the human skin and hair generally contain, above all, oil components and water. The oil components/emollients used include, for example, hydrocarbons, ester oils and vegetable and animal oils/fats/waxes. In order to meet stringent commercial requirements in regard to sensory properties and optimal dermatological compatibility, new oil components are continually being developed and tested.
Oils with good spreading properties are highly rated in the cosmetics industry because they are a key factor for sensorially-light preparations. Important representatives of this group are the isopropyl esters, such as isopropyl myristate (IPM) and isopropyl palmitate (IPP). Unfortunately, cosmetic chemists frequently criticize this group of products for their negative sensory impression, i.e., a distinctly audible grating sound when rubbed onto the skin and an associated unpleasant dry sensory impression. In addition, the isopropyl esters have the disadvantage of a comedogenic potential.
Other known oil components include fatty acid esters of 2-ethylhexanol, such as, for example, the esters of 2-ethylhexanol with stearic acid (C18), which are commercially obtainable under the INCI name of ethylhexyl stearate (for example, Cetiol® 868 from Cognis; Crodamol® OS from Croda Inc. and Estol® 1514 from Uniquema).
Other known oil components include fatty acid esters of 2-ethylhexanol with lauric acid (C12, dodecanoic acid) which are commercially obtainable under the INCI name of ethylhexyl laurate (for example, AEC ethylhexyl laurate from A. & E. Connock Ltd. and Estol® 3613 from Uniquema). Also known are fatty acid esters of 2-ethylhexanol with myristic acid (C14, tetradecanoic acid), which are commercially obtainable under the INCI name of ethylhexyl myristate (for example, AEC ethylhexyl myristate from A. & E. Connock Ltd.). In addition, coconut oil fatty acid esters of 2-ethylhexyl hexanol are commercially obtainable under the INCI name of ethylhexyl cocoate (for example, Crodamol® OC from Croda Inc.). The product is a 2-ethylhexyl fatty acid ester with fatty acids of coconut oil. The fatty acid distribution of coconut oil has the following typical composition: C12 (dodecanoic acid, lauric acid): 45-to-53%, by weight; C14 (tetradecanoic acid, myristic acid): 15-to-21%, by weight; C16 (palmitic acid): 74-to-11%, by weight; C18:1 (oleic acid): 6-to-8%, by weight; C18 (stearic acid): 2-to-4%, by weight; C10 (decanoic acid): 5-to-10%, by weight; C8 (octanoic acid): 5-to-10%, by weight, C6 (hexanoic acid): under 1%, by weight (source: Ullmanns Encyclopedia of Industrial Chemistry, 2005, Wiley & Sons).
EP 0 732 912 B1 (WO 95/15743) describes mixtures of Guerbet alcohols with 2-ethylhexyl esters based on a fatty acid with the following C-chain distribution: >3%, by weight, C14; 45-to-53%, by weight, C16; 43-to-52%, by weight, C18; and <2%, by weight, C20.
The problem addressed by the present invention was to find a high-spreading oil which, as an oil component itself and in cosmetic and/or pharmaceutical preparations, leaves a smooth impression behind on the skin, imparts very little stickiness, rather high softness and no comedogenic potential. It has surprisingly been found that an ester mixture based on 2-ethylhexanol with fatty acids having a particular fatty acid distribution solves the problem addressed by the invention.